Baltimore County moved one step closer on Tuesday to supporting an incentive package to Amazon.com Inc. to open a large fulfillment center at Tradepoint Atlantic. The Baltimore Business Journal first reported in July that Amazon had been in talks to open a warehouse at the former Sparrows Point steel mill site. For the Tradepoint Atlantic deal, the Baltimore County Council on Tuesday discussed a proposed resolution in support of a state loan of up to $2 million to attract the giant internet retailer to Dundalk at its regular work session.